C#： enum

C#的枚举类型跟C++差不多，一般我们将enum设为单个状态，比如enum color_t { RED, BLACK, GREEN}, 只能选择一个

而有的时候枚举可以作为位运算来进行与或运算，比如ControlStyles这个枚举，看下面一段从TabControlEx中的一段代码

            base.SetStyle(
                 ControlStyles.UserPaint |
                 ControlStyles.OptimizedDoubleBuffer |
                 ControlStyles.AllPaintingInWmPaint |
                 ControlStyles.ResizeRedraw |
                 ControlStyles.SupportsTransparentBackColor,
                 true);
             base.UpdateStyles();       

这里我自己写了一段代码来看个别位是否设置了

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;

 namespace test4
 {
     class Program
     {
         public enum ChangedTypes
         {
             Created = 0x0001,
             Deleted = 0x0002,
             Changed = 0x0004,
             Renamed = 0x0008,
             Added = 0x0010
         }
         public class Image
         {
             private ChangedTypes types;
             public ChangedTypes Types { get; set; }
         }

         static void Main(string[] args)
         {
             Image image = new Image();
             image.Types = ChangedTypes.Created | ChangedTypes.Changed | ChangedTypes.Added;
             if ((image.Types & ChangedTypes.Created) == ChangedTypes.Created)
             {
                 Console.WriteLine("image has been Created");
             }
             else
             {
                 Console.WriteLine("image has not been Created");
             }
             if ((image.Types & (ChangedTypes.Created | ChangedTypes.Changed)) == (ChangedTypes.Created | ChangedTypes.Changed))
             {
                 Console.WriteLine("image has been Created and Changed");
             }
             else
             {
                 Console.WriteLine("image has not been Created or Changed");
             }
         }
     }
 }